Implanon® is a contraceptive implant that is inserted in the human body for periods up to 3 years. Cases have been reported in which the implants could not easily be removed due to either incorrect insertions by physicians or due to non-insertion of the implant by physicians. Implanon can be visualized in the body using ultrasonography and MRI techniques. Visualization by MRI is not always readily available, relatively complicated and expensive. Visualization by ultrasonography is also not always readily available and may be difficult in the hands of inexperienced physicians especially in the event the implant was inserted incorrectly.
The implant should be removed (and replaced) after three years. Furthermore, women may want to remove the implant if they wish to become pregnant. Another reason for removal can be disease, such as cancer, especially breast cancer, ovary cancer or cancer of the uterus.
It would therefore be convenient to have an Implanon-like implant which will be X-ray visible. This in order to have additional methods to locate and identify the implant, either to facilitate removal of the implant or to be able to reassure the patient that the implant has been inserted.
Such a contemplated X-ray visible implant must be such that the radio-opaque component does not (i) influence the hormone release profile of the implant and (ii) does not migrate into the body through the open-ended implant.
X-ray visible medical devices, such as stents, catheters, intra-uterine devices such as MultiLoad®, biodegradable implants and dental devices are known. An X-ray visible drug delivery device known in the field of contraception is described in GB 2168257 which shows an X-ray visible vaginal ring comprising the progestogen levonorgestrel. GB2168257 does not relate to the influence of the radio-opaque component on the release rate of levonorgestrel from the ring, nor does such a ring have open-ends.
It is however crucial to ascertain that the hormone release rate is not significantly affected by a radio-opaque component present in the contraceptive device because that could possibly result in pregnancy, the unwanted effect for a woman using contraception.
Moreover, it is also crucial that a radio-opaque component present in the contraceptive/HRT device does not migrate outside the (open-ended) implant into the body in undesired amounts causing potential radio-opaque component related adverse effects.
Thus, the subject invention provides for a contraceptive and/or HRT X-ray visible implant wherein the radio-opaque component does not negatively influence the release rate of hormones from the device and does not migrate into the body.